The present invention relates generally to yarns, fabrics and protective garments knitted of such yarns and, more particularly, to an improved cut resistant support yarn suitable for wrapping with an additional yarn covering.
Certain technological advantages of various configurations of yarns, for use in protective garments, and technological advantages of certain fibers which be utilized in yarns for protective garments are known, for example from U.S. Pat. No. 4,777,789. This patent describes numerous uses for cut-resistant yarns and garments such as gloves and aprons for the meat processing industry. Other uses of cut resistant fabric include cut resistant jackets for surrounding a less cut resistant member, such as a rope, webbing; strap, hose, inflatables, and the like. Such cut resistant jackets are disclosed in U.S. Pat. Nos. 4,886,691 and 5,119,512. Other uses of cut resistant yarns may include a protective uniform such as worn by law enforcement officers a those involved in hazardous activities a hazardous sports, and knee and elbow protection pads for cyclists and the like.
However, prior to the present invention, there was a need to provide a support yarn consisting of cut resistant fibers that could be wrapped or spun with an additional yarn in a subsequent covering procedure.
The present invention provides a new cut resistant support yarn or core yarn that can be subsequently wrapped with an additional yarn covering to form a cut resistant yarn that can be weaved or knitted into a protective fabric usable as a rope, webbing, strap, hose, inflatable, jacket, glove, protective uniforms, and knee and elbow protection pads for cyclists and the like.
It is a further object of the invention to provide a new approach for making a cut resistant support yarn that can be covered with a subsequent yarn covering.
It is yet another object of the present invention to provide a cut resistant support yarn using a minimal number of strands.
The above and other objects are accomplished according to the invention by the provision of a cut resistant support yarn suitable for wrapping with an additional yarn covering. The cut resistant support yarn includes a core strand comprised only of a first cut resistant strand, a second cut resistant strand wrapped in a first, preferably clockwise direction around the core strand, and a third cut resistant strand wrapped in a second direction around the core, opposite to the first direction. One of the second and third cut resistant strands forms an inner covering surrounding the core, and the other of the second and third cut resistant strands forms an outer covering surrounding the core and the inner covering.
Preferably, the first cut resistant strand, the second cut resistant strand and the third cut resistant strand are wire which may be stainless steel.
Further, preferably the first cut resistant strand, the second cut resistant strand, and the third cut resistant strand each consists of one wire.
Although all of the cut resistant strands may be composed of the same cut resistant material, such as stainless steel, the first cut resistant only and at least one of the second and third cut resistant strands may also be comprised of different thickness of stainless steel.
Typically, the first cut resistant strand has a diameter generally in a range of 0.002 inches only 0.005 inches, and is preferably generally about 0.0036 inches. Further, the second and third cut resistant strands each have diameters generally in a range of 0.0015 inches to 0.0036 inches, and are typically generally about 0.0030 inches.
One of the second and third cut resistant strands in generally wrapped around the first cut resistant strand between about 9 to 21 turns per inch to form the inner covering, and the other of the second and third cut resistant strands is wrapped around the first cut resistant strand and the inner covering between about 7 to 19 turns per inch to form the outer covering.
To form the protective fabric, an additional yarn covering typically surrounds the cut resistant support yarn. The additional yarn covering comprises a wrapped outer yarn, or a spun yarn, and is preferably fibrous.
The present invention also contemplates a method of making a cut resistant yarn. A core comprised only of a first cut resistant strand, and second and third cut resistant strands are provided. One of the second and third cut resistant strands is wrapped in a clockwise direction around the core, and the other of the second and third cut resistant strands is wrapped in a counter clockwise direction around the core. An inner covering surrounding the core is formed in connection with one of the wrapping steps, and an outer covering surrounding the core and the inner covering is formed is connection with the other of the wrapping steps. These steps form a support yarn for a subsequent covering, which is either wrapped a spun around the support yarn.
The invention will be described below in greater detail in connection with embodiments thereof that are illustrated in the drawing figures.